There is known a number of dolls which respond to external stimuli and are intended to provide a life-like response.
U.S. Pat. No. 4,675,519 which issued Jun. 23, 1987 to Price describes a toy having an optically actuated sound generator. The patent specification discloses a doll having two optical sensing circuits including optical sensors in the eyes of the doll. The arrangement is such that a variation in sounds emitted from the doll is caused by a change in relative light intensities striking the sensors.
U.S. Pat. No. 4,249,338 which issued Feb. 10, 1981 to Wexler describes a doll having a sound generator and a number of switch means. There is a first switch for causing the doll to start to cry and other switches to stop the doll from crying, such as one located so as to be actuated by patting the doll's back.